1. Field of the Invention
This invention relates to a photodiode as a light receiving device and photodiode module combining a photodiode and a light emitting device for bilateral or unilateral optical communication of information between a base station and a plurality of subscribers by transmitting two light signals having different wavelengths .lambda.1 and .lambda.2 in a unilateral direction or bilateral directions passing through an optical fiber.
This application claims the priority with respect to Japanese Patent Application No.256107/1997 filed on Sep. 3, 1997 which is incorporated herein by reference.
2. Description of the Related Art